Electromagnetic induction - A.C. generator

Electromagnetic induction is change in ___________________. 

• surface area
• magnetic poles
• magnetic flux

Voltage can be induced in a wire by

• a. moving the wire near a magnet.
• b. moving a magnet near the wire.
• c. changing the current in a nearby wire.
• d. all of these

Which activity will produce the highest current?

• Move the magnet bar into the coil while the coil remains stationery

• Move the coil into the magnet bar while the magnet remains stationery

• Move the coil and magnet towards each other

• Move the coil and magnet away from each other

Which action will increase the deflection of the galvanometer pointer?

• The magnetic pole is reversed

• The number of turns of coils is increased

• The coil is made from insulated wire

• The magnet is slowly pushed into the coil

The production of electric current by a changing magnetic field is called ____________________________________.

• induced current

• electromotive force

• electromagnetic induction

• internal resistance

Which device uses slip rings?

• a cathode-ray tube

• a D.C. motor

• an A.C. generator

• a solenoid

When there is a change in the magnetic field in a closed loop of wire

• (a) a voltage is induced in the wire
• (b) current is made to flow in the loop of wire 
• (c) electromagnetic induction occurs
• (d) all of these

The A.C generator makes use of electromagnetic induction to produce _______________________

• force

• electricity

• energy

• power

Which of the following increases frequency of AC?

• increasing number of turns on the coil

• using a stronger magnet

• rotating the coil faster

• increase area of the coil

Which of the following best describes electromagnetic induction?

• the production of a capacitance across an electrical conductor in a changing magnetic field

• the production of a potential difference across an electrical conductor in a changing magnetic field

• the production of a resistance across an electrical conductor in a changing magnetic field

• the production of an electromotive force across an electrical conductor in a changing magnetic field